By Anna Mehler Paperny OTTAWA (Reuters) – Sleeping in trucks and staying warm at fire pits and portable saunas, protesters camped out in the frigid Canadian capital of Ottawa are digging in for a long stay, convinced they have momentum and right on their side. The number of protesters in the “Freedom Convoy” – initially an opposition to vaccine mandates for cross-border drivers that has morphed into a wider protest against COVID restrictions and the Canadian government – has thinned since it arrived in Ottawa 12 days ago. “We want freedom for our kids,” said Jean-Pierre Lapointe, who came from…